With respect to tennis, up the present time tennis players have been limited to three methods of solo practice, which, for a variety of reasons, do not meet their needs:
(1) The ball machine. This an excellent method but requires very costly equipment which pneumatically powers balls, in sequence, to the player on a full size court. A ball machine is not within the means of the average player for regular practice sessions. PA1 (2) False walls or netted frames to rebound a struck ball back to the player. The space requirement of the practice area limits availability. In addition to this, the average player cannot maintain the repetitive trajectory that is essential to a consistent stroke that will build muscle memory. PA1 (3) A motionless ball sitting in an apparatus ready to be struck by a racket. This does provide practice for the basic mechanics of a tennis stroke. However ninety percent of miss-hit strokes are related to footwork and the inability of a player to time the racket movement to coincide exactly with ball speed, so that the ball will be struck at the exact instant required for a perfect return.
Ball striking practice devices are well known in the prior art. Of particular reference to the present invention are U.S. Pat. No. 2,713,487 of Jaediker issued Jul. 19, 1955 and U.S. Pat. No. 4,089,521 of Berst et al issued May 16, 1978. Both of these references teach tennis practice devices comprising base-mounted pivoting posts which support tennis balls at their free ends, and in which the posts are biased to return to an initial position when the ball has been hit causing the posts to pivot away from that position. Such constructions have tended to be large and unwieldy, with heavily weighted bases to withstand the impact of the ball being hit and the pivoting motion of the post. As well, the positioning and amplitude of the post remains fixed, dictated by the construction of the device.
Other references of general background interest describing and illustrating ball striking practice devices include U.S. Pat. No. 1,670,174 of Richards issued Jul. 31, 1928, U.S. Pat. No. 2,578,313 of Moseley issued Dec. 11, 1951, U.S. Pat. No. 3,876,203 of Gold issued Apr. 8, 1975, U.S. Pat. No. 3,794,320 of Salmont issued Feb. 26, 1974, U.S. Pat. No. 3,924,853 of Schleeger issued Dec. 9, 1975, U.S. Pat. No. 4,204,678 of Weis issued May 27, 1980, U.S. Pat. No. 4,417,730 of Weiner issued Nov. 29, 1983, U.S. Pat. No. 4,508,339 of Llewellyn , U.S. Pat. No. 4,508,340 of Liao issued Apr. 2, 1985, U.S. Pat. No. 4,531,734 of Herrick issued Jul. 30, 1985.